Ningbo, China · air movement since 1990
China centrifugal blower manufacturer, built to your drawing
Forward-curved, EC, DC and combustion blowers from Ø24 to Ø500 mm for OEM equipment makers. Send a drawing or a duty point; you get a model, a P-Q curve with your operating point marked, and a sample in 1–3 days.
- One drawing owner, one inspection standard, one invoice — whichever line builds it
- Samples 1–3 days on catalogue models, production 15–30 days, 12-month warranty
- Your label, your carton, your connector — OEM from the first article
Five blower lines, one specification owner
Every line below is a scroll-housed centrifugal blower with the wheel sitting straight on the motor. Pick by what your unit has to move; the model is matched to your duty point before we quote.
Forward-curved squirrel cage blowers
The main family: AC, EC and DC, with or without a volute, single or double inlet.
- Wheel
- Ø108–500 mm
- Supply
- 220/230/380 V AC
- Airflow
- 206–9,064 m³/h
EC centrifugal blowers
Integrated drive, stepless 0–10 V or PWM, about 30% lower consumption at part load, confirmed against the load profile.
- Wheel
- Ø108–355 mm
- Power
- 42–2,400 W
- Speed
- 760–3,650 rpm
DC brushless blowers
For equipment with no mains bus: battery, solar, 310 V DC bus, medical and mobility products.
- Wheel
- Ø120–197 mm
- Supply
- 24 / 48 / 310 V DC
- Control
- 0–10 V, PWM, FG
Gas & combustion blowers
Sealed combustion air for condensing boilers, wall-hung boilers, water heaters, premix and pellet burners.
- Blade
- Ø77–180 mm
- Pressure
- up to 4,100 Pa
- Supply
- AC, DC 12/24 V, EC
Single inlet centrifugal blowers
The narrow package for fan heaters, convectors and small cabinets, in three size bands.
- Wheel
- Ø120–315 mm
- Power
- 54–2,200 W
- Airflow
- 206–5,150 m³/h
Wheels, impellers and volutes
Forward-curved wheels, cross-flow impellers and empty housings supplied to drawing as components.
- Material
- Steel, aluminium, PP/PA
- Balance
- G6.3 or G2.5
- Basis
- Project / drawing
How an OEM blower project runs
Six steps from your first e-mail to a labelled carton. Nothing is tooled before you have seen the cost and the break-even.
- Drawing or duty point
A 2D or 3D drawing, or just the numbers: airflow, static pressure, voltage, control mode, envelope, noise limit.
- Model proposal and P-Q curve
One or two models with your operating point marked, the input power there, and what must change to fit your envelope.
- Sample
One to three days for a catalogue model. A new wheel width or a modified volute takes longer, and the date comes with the quote.
- Tooling, if needed
A new impeller, volute or bracket means a mould or press tool — quoted with cost, lead time and ownership before anything is cut.
- First article
Dimensional report, electrical safety run-off, balance record and a measured P-Q curve, against the signed drawing.
- Production
Fifteen to thirty days, your label and your carton, warranty twelve months.
Made here, and made to our drawings elsewhere — stated plainly
It decides how you audit us, so it is on the front page rather than buried. Cross-flow fans are built on our own line in Yuyao, on LONGWELL drawings with our own moulds and impeller tooling. The motor winding line is ours as well: automatic winding, coil insertion, inter-turn insulation test and argon-arc welding of the lead wires, audited during the 2021 ETL factory audit. Every other blower line here is engineered and specified by LONGWELL, built to LONGWELL drawings in qualified partner plants, inspected to LONGWELL standards, then labelled and shipped under LONGWELL.
What every blower passes before it is labelled
Own line or partner plant, the inspection documents are the same.
Every rotating assembly is balanced; EC and DC data sheets call for ISO G6.3.
Earth continuity, dielectric withstand, insulation resistance, then a run test — unit by unit.
Tested to the AMCA 210 method; that is how the P-Q curve you receive is produced. Tested to the method is not AMCA certified, and we do not claim to be.
Measured in a semi-anechoic room, calibration report SSD202500326.
Quoted L10 at a stated temperature: 20,000 h at 70 °C on LWFE3G250-138DS-02, 30,000 h at 40 °C on the direct-drive range. Compare only at the same temperature.
CE covers AC forward-curved LWFA108–450; ETL 5022563 covers part of the EC and DC range. Name the model and we confirm the scope in writing — see quality & certifications.
On the test bench, not on a datasheet
The bench runs 2,500 to 38,000 m³/h against 0 to 3,000 Pa. Your model is measured point by point to the AMCA 210 method, and the curve you get in the quotation is that run — with your duty point marked on it.
Inter-turn insulation test, stator by stator
Wound stators go to the surge bench before they are built into a rotor: the waveform on the screen is what separates a good winding from one that will fail in the field. The same bench records the result against the batch.
Where these blowers are fitted
Most of what leaves here goes inside somebody else's product. Typical duty: 200–9,000 m³/h against 150–1,100 Pa, or up to 4,100 Pa on combustion.
Air purifiers & FFU
Low-noise EC and DC volute blowers sized against a loading filter, not a clean one.
Gas boilers & water heaters
Combustion air and flue-gas duty with the temperature limits stated per model.
Fan coils & small AHUs
Single and double inlet blower assemblies matched to cabinet depth.
Electric heaters & convectors
Compact single-inlet blowers with tapped AC speeds or stepless EC.
Cabinets, inverters & telecom
DC blowers on 24, 48 or 310 V with FG tacho and locked-rotor protection.
Refrigeration & heat pumps
Evaporator and cold-room duty where the blower runs wet and cold all season.
Tell us the duty point. We will tell you the model.
Airflow, static pressure, voltage and control mode are enough to start. A drawing is better. An engineer answers, not a mailbox — usually within one working day, GMT+8.
Common questions
Can you build a blower to my drawing?
Yes. Send the drawing with the numbers it has to hit. We check it against existing wheel and volute sizes first, because a catalogue wheel in a modified housing beats a new tool on cost and time — and if nothing fits, we say so before quoting tooling.
Which certificate covers the model I am buying?
ISO 9001 (BMCQ0222448M), ISO 14001 (BMCE0222279M) and ISO 45001 (BMCS0222232M) run to 8 December 2028 and cover the company. Everything else is scoped to models. The KTS CE certificates — LVD KB2207084L01, EMC KB2207085E01, RoHS KB2207086R01 — cover the AC forward-curved LWFA108 to LWFA450 range; the 455 and 500 sizes fall outside them, and none of the EC, DC, cross-flow or gas lines is in that scope. ETL Recognized Component control number 5022563 covers part of the EC and DC range. Name the model and we confirm the scope in writing.
Can you supply the wheel or the volute on its own?
Yes, as a component to drawing: forward-curved wheels in galvanised steel, aluminium or reinforced plastic, cross-flow impellers, inlet rings and empty housings. Sizes and how to specify one are on the blower wheels and impellers page.
Can I see the curve and the CAD before I order?
Yes. Model pages with P-Q curves, dimensions and CAD downloads are on select.longwellfans.com. Give us the operating point and we mark it on the curve for you.
What happens if a blower fails in the field?
You contact us, not a plant you have never heard of. We hold the drawing, the first-article report and the inspection record for your part number, so a failure is traced to a batch. Warranty is 12 months.
Send your drawing or duty point
Upload a drawing, a spec sheet or a photo of the blower you are replacing. Files up to 12 MB: PDF, DWG, DXF, STEP, Excel or an image.
Request a quote
Send your duty point or a drawing. You get a model proposal, a P-Q curve and an FOB price — usually within one working day.